MIDI Output Not Working via Bluetooth to AirStep (Works with Other Apps & USB)

rrooding

Hi Peter,

I’m having an issue with MIDI output from Stage Traxx 4 on my iPhone. MIDI messages are not being sent to my Bluetooth MIDI device (AirStep), even though everything is configured correctly and forwarding works with other apps.

My Setup:

Stage Traxx 4 (4.0.13 (2787)) on iPhone running iOS 26.5
iPhone connected via Bluetooth MIDI to XSonic AirStep
AirStep is set to forward all incoming MIDI messages to all outputs
AirStep → CME WIDI Jack (Bluetooth) → Quad Cortex Mini
AirStep and WIDI Jack are both on the latest firmware

What Works:

MIDI messages from Stage Traxx 4 are visible in MIDI Wrench (with background monitoring enabled)
Forwarding works perfectly with other MIDI apps (e.g. MIDI Wrench) — messages successfully reach the Quad Cortex
The exact same Stage Traxx 4 project works correctly when using my MacBook connected via USB MIDI to the same setup
MIDI commands are only set in the Lyrics section

What Doesn’t Work:
Stage Traxx 4 does not send any MIDI messages through the Bluetooth connection to the AirStep, even though the device appears connected.

Screenshots:

List of available Bluetooth MIDI devices in Stage Traxx 4

MIDI Settings screen

MIDI Output ports selection

AirStep forwarding / MIDI routing configuration

I would really appreciate any advice on why Stage Traxx 4 is not outputting MIDI via Bluetooth MIDI in this configuration, while other apps work fine and USB MIDI from the Mac also works.
Thank you in advance for your help!

peter

I don't have an Airstep. All I can say is that your MIDI settings in ST4 look OK. The Airstep is clearly recognized and shown in the Output ports section and you have also enabled it. So from that perspective the configuration in ST4 is correct. May be something in the Airstep settings.

rrooding

I did some additional testing and found something interesting:

If I add a MIDI file in Stage Traxx 4 and assign it to the correct output port, the MIDI commands do get sent correctly and are successfully forwarded by the AirStep to the Quad Cortex.
However, the MIDI commands I have set directly in the Lyrics section still do not get sent via Bluetooth to the AirStep.

I also tested with several other MIDI apps on my iPhone — they all work perfectly with the AirStep (messages are forwarded without any issues). The same problem occurs when I run Stage Traxx 4 on my MacBook connected to the AirStep via Bluetooth MIDI, while other applications on the MacBook send MIDI through the AirStep without problems.
This makes me think there might be a bug or compatibility issue specifically between Stage Traxx 4 and the AirStep when using Lyrics-based MIDI triggers.

I’d be happy to provide any additional information that could help debug this — such as logs, more detailed screenshots, or testing specific settings if you can let me know what I should check.
Thanks again for your help!

Lishy

rrooding sounds like it might be an issue with your midi messages in the lyrics editor. Can you post a screenshot?

rrooding

Lishy Sure, I am using the on load midi messages to select a preset on my Quad Cortex. And like I said, these midi messages do work when connected over USB directly to the Quad Cortex.

Here is how I configured it:

I just did one more test. If I enable the MIDI Clock in Stage Traxx, then that MIDI is also transmitted to the Quad Cortex. The only thing not coming through is MIDI from the lyrics section.

I also tried with other variants
[midi@00:04: PC6.1@1] [midi@play: PC6.1@1]
but those don't come through either.

Midimannz

rrooding Try placing a time code into your midi [midi@00:00.20 PC06.1@1]

peter

The midi command looks fine. That should work right out of the box.

rrooding

I agree the MIDI command itself looks correct, and it works perfectly when using a wired USB connection directly to the Quad Cortex.
The problem is isolated to Lyrics-based MIDI over Bluetooth:

MIDI Clock and MIDI File triggers do transmit successfully through the AirStep.
Other MIDI apps on both iPhone and MacBook send MIDI reliably via the AirStep.
Only the MIDI commands entered in the Lyrics section fail to go through when using Bluetooth MIDI (AirStep + WIDI Jack).

Since the AirStep is correctly detected and other MIDI types work, it seems there might be a specific incompatibility with how Stage Traxx 4 handles Lyrics MIDI over Bluetooth MIDI connections.
Would you have any ideas on what could cause this or what I could test next to help narrow it down?
Thanks again!

peter

There is no general lyrics based midi bug for bluetooth connections. I (and many others) use that all the time. So I have unfortunately absolutely no idea why it is not working for you. Sorry.

peter

That command won't work. It is missing a :. Corrected it would be: [midi@00:00.20: PC6.1@1]

rrooding

Thank you for your patience with this issue.
I’ve continued debugging and found a few important things:

A simple Program Change does work over Bluetooth:
[midi: PC6@1] successfully triggers a preset change (WIDI Jack LED flashes and Quad Cortex responds).
However, any attempt to send Bank Select + Program Change (which I need for proper preset recall in Setlist 1) fails when sent.

I was able to reproduce the exact same behavior using the sendmidi tool on my MacBook:

This works (messages arrive and preset changes):
sendmidi dev "AIRSTEP Bluetooth" ch 1 cc 0 0 +00.050 cc 32 1 +00.050 pc 2

This does not work (no LED flash, nothing arrives):
sendmidi dev "AIRSTEP Bluetooth" ch 1 cc 0 0 cc 32 1 pc 2

It seems the AirStep’s Bluetooth forwarding drops the messages when they are sent too quickly one after another, but accepts them if small delays are added between CC0, CC32, and PC.
For now I’m using simple [midi: PC6@1] as a temporary workaround, but I would really like to get full Bank Select + PC working, as it works perfectly over USB.

I will also send an email to XSONIC AirStep support about this forwarding behavior.

Would it maybe be possible for Stage Traxx to send the MIDI with slightly more delay (maybe configurable) between messages?

Thanks again!

peter

Great findings. MIDI devices often seem to be really picky regarding the receive timing. For now I would suggest you run those commands as timed midi commands at the start of the song:

[midi@00:00.00: CC0.0@1]
[midi@00:00.05: CC32.1@1]
[midi@00:00.10: PC2@1]